Recently, a relay operation has been introduced to a wireless local area network (WLAN) to expand a coverage range of an access point (AP) and reduce power consumption of a station. When the AP transmits data to the station, transmission efficiency may decrease due to an obstacle present between the AP and the station. Also, when the station transmits data to the AP, the station may not appropriately transmit the data to the AP although the station receives the data from the AP because transmission power of the station is lower than that of the AP. Thus, a relay may be used to solve such an issue and expand a coverage range for transmission performed between the AP and the station.
A conventional relay may mainly use a channel identical to a channel used by a root AP. That is, a root basic service set (BSS) set up by the root AP and BSSs set up by relays may operate in an identical channel. In such a case, the root AP BSS and the relay BSSs may overlap to result in an overlapping BSS (OBSS) issue, and contend or collide with one another. Thus, using the relay may lead to a greater frequency of contention and collision between the root BSS and the relay BSSs due to the OBSS despite an extended range for transmission.